Thank God – or school administrators, or Dr. Gary Foster, or kids who just want to have fun – thank anyone you want… but there’s finally some good news about childhood obesity. It came on June 27, at the annual meeting of the American Diabetes Association.

The results of the three-year HEALTHY Study are in, and while they might not be exactly what researchers hoped for, they’re plenty good. A three-pronged middle school program that improved food in schools, jacked up gym classes, and made it “cool” to be healthy, helped husky 6th-graders slim down by the time they were headed off to high school.

Technically, the study didn’t succeed – that is, it did not meet the primary endpoint of decreasing the prevalence of a combination of overweight and obesity at target schools more than control schools. But by the end of the intervention, HEALTHY schools did have fewer kids with extremely high waist circumference, and fewer with a body mass index above the 95th percentile.

The program seemed to work best in the kids who were already overweight or obese as 6th-graders. They were 21% less likely to be overweight or obese in 8th grade than students at the control schools. And they had a trend – though not a significant difference toward a greater reduction in the BMI z-score by grade eight.

Perhaps the best news in the study was its “failed” primary endpoint: By the end of the study both intervention and control schools saw significant decreases of 4% in the prevalence of kids who were overweight or obese. It’s not entirely clear why, but at a press briefing, Dr. Foster, a Temple University endocrinologist, suggested a few possibilities.

The control schools had the same enrollment procedure as the intervention schools: All the 6th-graders had a health screening that included weight, blood pressure, a lipid panel, and insulin and fasting glucose levels. All the parents got a “health report card” describing their child’s status and suggesting a doctor visit if indicated. That might have been enough to stimulate some family changes that helped children shed pounds.

Just as likely, he suggested, are societal trends. Maybe word of the looming avalanche of obesity-related diabetes, cancers, and cardiovascular disasters has finally penetrated the cacophony of advertisements suggesting that kids can live off the “Children’s Menu” diet – chicken fingers, french fries, and a soda.

Whatever the reason, I’m thrilled: Last year, my son wanted to celebrate his 13th birthday by taking some buddies to a theme park . Two of them — one “husky” and one frankly huge — couldn’t take the strain of walking around a slightly hilly park on a warm late-April day. The bigger one ended up in the nurse’s station for 4 hours with a splitting headache and an upset stomach.

It was a lesson learned for my son, though. He has moderated his own diet noticeably since then, referring several times to how sad it was that his lifelong, overweight friend couldn’t keep up, even in the race to have fun.